Sleeve valve for a four stroke opposed piston engine



E. SCHMID an. l1, 1938.

SLEEVE VALVE FOR A FOUR STROKE OPPOSED PISTON ENGINEu Fled'Jan. 22, 1936 Patented Jan. 1.1 l f UNITED STATES 'sumva vALvn 'ron A Formy smoke orrossnrrs'ron ENGINE Ernst Schmid, Annecy, Haute-.Savoia France .Application January zz', 193s, serial No.- cassa" In Germany February 5,1935

c claims. (c1. 12s-51)' My invention. relates to improvements "in a. sleeve valve for a four-stroke opposed piston engine; and the objectsl oi my improvement are, iirst, to prevent the piston'rings from raking the ports ofthe valve, and,l second, to preventthe piston rings from getting stuck fast to the valve I attain these objects by providing the' valve with ports all lying at the' same height and have it move only between the runways o! thetwo sets of piston rings; all of which becomes evident from the accompanying drawing, in which- Fig. 1 isa vertical section of a twin-cylinder; Fig. 2 shows the position or the sleeve valve, in

'15 vertical section, during the moment of exhaust; l Fig. 3 shows the'position or the sleeve valve.

. in vertical'section, during the moment of explosion; and

Fig. 4 shows the initial positionof the sleeve valve,` invertical section;

I and T are two cylinders lying in' line and .'opposite and being rigidly interconnected, in`

which the pistons 3 and provided with sealing xrings 5 are beingoperated in opposite sense by crankshaits 6. v1 isthe. placeof explosion common to both cylindersl and 2 (Fig. 3). Between the -cylinder wallsand the p'lstonswe'h'ave a thin-walled. sleeve valve 8 being subjected to an A 'unequally oscillating Jm'ovement, -in a well-w 3o knownjmannenby-wayoi drive I0, I I is the intake and I .2 .theexhaust l'a'nd Il are the spark plugs. .'Ihe sleeve valve `A 8 possesses in .its

' middle a sole series oi ports Iiiv with which the steering of intake II and exhaust I2 is effected.

'rneedges'n of ports l5 extending at right angles to the lcylinder axis lieoutside thatv part A of the inner cylinder wall which is rakedby -pistons-Sand l (Figs.`24)1sothat a. stickingfiast of the' piston rings 5 to ports I5 cannottake 40 place.4 In order to seal the valve by means of the inside pressure. at the time of compression, edges I1 of ports l5 are provided with slits I6.' Since'.

y .the pistons move in opposite ydirections, all

lateral pressures of the pistons against valve '8 are eliminated,V which lattercircumstance proves to be of substantial advantage.

' Besides the advantagesreferred to my .inv'en-v 'tion 'has-yetvthe advantage that thel ports may receive relatively large cross-sections and this.

so much more as each of the two edges I'I eithersteers the exhaust 'or' the intake. The. structural realization of my design furthermore is' very simple. V;

I claim.: 1. In an internal combustion engine o! the four-stroke opposed piston typ'e the combination comprising a cylinder having .axially spaced inlet and exhaust ports, a sleeve valve havinga port in a single plane slidable axially within said cylinder, said port in said valve' alternately per-l -5 -mitting communication between said" inlet and exhaustp'ortsjto' the interior of lsaid sleeve valve,

pistons reciprocating i-n opposed `directions within said sleeve-valve, piston rings on said pistons and'said port in said valve being so positioned l0 that it remains always between said piston. rings and is notwiped thereby. 2. In an internal combustion engineof the four-'stroke opposed piston type the combination comprising a 4cylinder having axially spaced inlet 1 5 and exhaustports, a sleeve valve having a portin` a single plane slidable axially within saidcylinder, said port-in said valve alternately pen` `mitting communication between said inlet and exhaust ports tothe interior of said sleeve valve, 26 pistons reciprocating in opposed directions with- -.in.said sleeve valve, anda spark plug located in 'said cylinder wall intermediatetsaid exhaust and inlet portsand adapted to be uncovered by said sleeve valve port.4 v- 25 3.- In an internal combustion engine ofthe four-stroke opposedpiston type the combination comprising 'a cylinderjha'ving axially spaced inlet 4andexhaust ports, a sleeve valve' having a series of portsin a single plane -slidable axially within 30 said cylinder, saidports in said valve alternately permitting communication between said inlet and exhaust.A ports to the interior, of said sleeve valve, pistons reciprocating i'n opposeddirections "within said sleeve valve. piston' rings on said 3'5 pistorisjsaid ports in said valveY being s o' positioned that they 'remain between 'said piston 1"" i I rings andare not wi thereby,andspark plugs located in said vcylinder wall intermediate saidv exhaust and inlet ports and said 'spark plugs A 401 l.cooperate with 'said' inlet and4 exhaust ports, said ,sleeve valveI being slidable axially within said 50 cylinden's'aid port in said v'alve alternately'perm'itting" communication -between said inlet and exhaust ports to .the .interior of said Asleeve valve.'l

pistons reciprocating in opposed directions withi Hin said sleeve valve, piston rings on said pistons, 55

and is not wipedtheeby.

5. In an internal combustion engine of the four stroke opposed piston type, the combination comprising a common cylinder having the same inner cross section throughout and having axially spaced inlet and exhaust ports, a sleeve A valve having a port in a single plane adapted to Ain said sleeve valve, and a spark plug located in said cylinder wall intermediatesaid exhaust and' inlet ports and, adapted to be uncovered bythe.

same sleeve valve port-which cooperates'with the inlet and exhaust ports. x

6. In Van internal combustion engine or the the inlet and exhaust ports.

and said 'port in said valve being so positioned I that it always remains between said piston rin'gs ltour-strokel opposed' piston type, the combina- .tion comprising a common cylinder having. the

same inner cross section throughout andhaving axially spaced inlet and exhaust ports, a sleeve valve having a series of ports in a single plane adapted to cooperate with said inlet and exhaust ports, said sleeve valve being slidable axially within said cylinder. said ports in said valve alternately permitting communication betweenl said inlet and exhaust ports tothe interior of said sleeve' valve, pistons reciprocating in opposed directions within .said sleeve valve, piston rings on said pistons, said ports in said valve being so positioned that they remain between f said piston rings and are lnot wiped thereby, and

spark plugs located in said cylinder wall intermediate said exhaust and inlet ports and said spark plugs being adapted to be uncovered by the same sleeve valve ports which cooperate with ERNST SI-ILMD. 

